Research on AO / FO batch management technology in aircraft production

Based on the analysis of the characteristics and significance of AO/FO in the process of aircraft production, this paper analyzes the format rules of AO/FO batch management from the perspective of technology realization, and details the AO/FO The change of the query and the change status tracking, introduces the AO/FO single-stand status display in the batch management, increases the structure definition of the attribute table in the batch management, and designs the relevant algorithm to store and calculate the batch information. Finally, based on the above theory support AO/FO batch management system successfully used in the production of a machine.


Introduction
Influenced by the small batch and the variety of production methods, the aircraft product production organization is put into production by batch, and the assembly process is organized according to the production.The technical state of the production is concentrated in assembly, and the main basis of product assembly is the assembly outline, namely AO.AO is an instructional process document which is written by the technical department according to the requirements of assembly technique, process level and quality assurance [1].MBOM is based on separation process surface based on product batch of vehicles management of manufacturing product structure view [10], some different types of aircraft sorties of MBOM may not be the same, before generated by the product code and batch of vehicles to find suitable for the vehicles of AO/FO [2][3].It also requires effective management of all kinds of data in the aircraft's batch production [3][4].
The development of early aircraft products is mainly based on single configuration, and simultaneously is affected by the first generation of CAPP software architecture.The aircraft manufacturers mainly manage AO/FO through the latest version of valid form.With the promotion of serialized and configured development mode of aircraft manufacturing, the traditional AO/FO management mode is no longer suitable for the management and control of aircraft technical state.From the technical realization perspective, this paper discusses the realization mode of AO/FO management from valid management of latest version to valid management of multiple versions based on shipset, and successfully applies this mode in the production process of a certain type of batch-produced aircraft.

Meaning of batch management
In a traditional CAPP system, there are multiple versions of AOs/FOs under the same component number, but the latest version is valid.If the aircraft from different shipset are produced simultaneously in a development process, the valid shipset management is required to be performed on different versions of AOs/FOs to realize the association of revision with batch and the simultaneously-valid multiple versions, thereby effectively guiding the production and assembly of parts from different batch, to guarantee the correctness and uniqueness of production data.
When AO/FO is required to be changed, the compiler has mastered the information about aircraft batch concerned with this change, and the corresponding valid AO/FO requires to be solved by means of the logical operation of batch validity management module of CAPP system.Because the multiple versions of AOs/FOs may be concerned in each change, this is a complicated recording process, and therefore, it is required that a change process must be traceable, which enables users to master the change process, functioning as prevention of change missing.
AO/FO batch management is also the management of aircraft configuration, and in the aircraft configuration, the principle that the latest revision is valid [4] is adopted, that is, when different batch of AOs/FOs are changed, the highest version of AO/FO of components in this shipset is the valid one.Reasonable management of AO/FO batch validity will aid in the improvement of the ability to manage and control aircraft state, such that the problem of design and manufacturing is disposed more accurately and effectively [5][6].

Batch management format rules
When inputting validity, necessary batch format rules must be agreed, to realize unified data rules, which functions as calculation and query.Table 1 lists several batch management forms."From" indicates this AO/FO is applicable to the production or assembly of this batch and its subsequent components; "Segment" indicates this AO/FO is applicable to the production or assembly of the batch components within a range.Batch information may be any one of the above three conditions to represent the only meaning, and may be any combination of the above three conditions to represent multiple meanings.
3 Changing and tracking of AO/FO batch information

Change
The query of AO/FO of a CAPP system component may be performed by the operator according to number localization or changing basis.According to different product processing states, the searched result may be divided into three conditions: (1) When a product belongs to a manufactured product from its processing state, the system displays all query results of the product, the compiler identifies the corresponding shipset (version) of AO/FO, works out the rework and repair AO/FO, and assigns the batch information to it; (2) When a product belongs to an in-process product from its processing state, the system displays all query results of the product, the compiler identifies the corresponding shipset (version) of AO/FO, creates a temporary amendment sheet, and assigns the batch information to it; (3) When a product belongs to a product to be manufactured from its processing state, the system displays all query results of the product, the compiler identifies the corresponding shipset (version) of AO/FO, needs to update the original AO/FO, computes the recommended batch according to logical algorithm, and assigns the batch information to it [7][8].

Tracking of change state
The compiler can look up the change state and the change process by locating AO/FO number and version, and gives a feedback for updating condition of a component's AO/FO to the compiler, including unchanged batch, changed batch, time of change, and changed version.

Single sortie state displaying
By displaying the single sortie state, the directory information display that AOs/FOs of a certain model of aircraft in a shipset are all effective is realized, mainly including two aspects of content.
(1) When displaying the single sortie state, the aircraft model, compilation unit and compiler corresponding to AO/FO are involved, and the authority of AO/FO department is divided and positioned; (2) The single sortie state may also be inquired and displayed by taking other process documents as input conditions, such as temporary amendment sheet, matching card, technical sheet, rework and repair AO/FO, as well as by means of AO/FO type (general, important and critical).

Query condition setting of single sortie state
The set query conditions mainly include model, batch, compilation department, compiler, type of process document, basis of compilation, etc., wherein the model is automatically loaded by the system, and is not editable in general; the batch is input by the operator, with the format rule automatically judged by the system.the department and the compiler are usually constant, and can be selectively input by the operator; process documents may include part number, matching card, temporary amendment sheet, technical sheet, rework and repair AO/FO, etc., one or more of which can be selected by the operator.The basis of compilation may be divided into process documents, process improved contents or other documents, one or more of which can be selected by the operator [9][10].

Query result of single sortie state
The system performs logical operations based on the set query condition to query out AO/FO and process documents for this batch within the range of the condition.The results of querying a directory mainly include AO/FO number, AO/FO version, document type and document name.

Structural definition of database
In this paper, it is recommended that oracle database be used for defining and storing batch management data, AO/FO data be structured, and table structural definition be added in the database, in order to record the generation, change and final result display of all batch information and for translation display of AO/FO batch management information.Refer to Table 2 for the structural definition of attribute table.

Table 1 .
Several AO/FO Batch Management Forms

Table 2 .
Structural Definition of attribute tableThe number INPUT_PLANNO, minimum shipset INPUTJC_MIN and maximum shipset INPUTJC_MAX are the data input by the operator; shipset change MODI will automatically increase with shipset change; the corresponding revision VER_FROM is from the structured data of the system; the variables ORA_MIN, ORA_MAX and VER_NOW are computed by system design logical algorithm.

Table 3 .
Attribute Table of Logical Algorithm Variable Definition of Batch ManagementWithin the scope of the same number and batch change, if the changed batch (JC_TO) is less than the minimum batch (INPUTJC_MIN) or the unchanged batch (JC_FROM) is more than the maximum batch (INPUTJC_MAX), indicating no eligible batch record, it is unnecessary to upgrade the original AO/FO, but it is necessary to establish new AO/FO with the steps as shown in Algorithm 1; if the unchanged batch (JC_FROM) is less than or equal to the minimum batch (INPUTJC_MIN), it is necessary to upgrade the original AO/FO as well as compute and store the corresponding batch information, and specific steps are shown in Algorithm 2. This section provides batch solving algorithms in two conditions:Algorithm 1: Establishment of New AO/FO Step1: Assign 0 to the AO/FO revision (VER_FROM) corresponding to the current batch; Step2: Increase the new AO/FO revision (VER_NOW) by 1; Step3: Assign the minimum shipset (INPUTJC_MIN) to the unchanged batch (JC_FROM); Step4: Assign the maximum shipset (INPUTJC_MAX) to the changed batch (JC_TO); Algorithm 2: Solving of Revision and Batch Step1: Record AO/FO where the unchanged batch is as R1; Step2: Regard new AO/FO revision (R1.VER_NOW) as the current AO/FO revision (VER_FROM); Step3: Increase the new AO/FO revision (VER_NOW) by 1; Step4: Assign the minimum shipset (INPUTJC_MIN) to the unchanged batch (JC_FROM); Step5: Compare the changed batch of R1 (R1.JC_TO) with the maximum shipset (INPUTJC_MAX); if the changed batch of R1 (R1.JC_TO) is less than the maximum